Previously, WelcomePageHandlerMapping would forward to index.html.
This assumed that the static path pattern was always /**. If it had
been customised to, for example, /foo/**, then the forward would still
be to index.html and a 404 would result as the page is actually
available at /foo/index.html.

At first glance, it would appear that the forward should be made to
foo/index.html. However, as it's a forward rather than a redirect,
any relative URLs in the index.html page would then be resolved using
/ whereas they should be resolved using /foo/. This could be addressed
by using a redirect rather than a forward, but we don't want to do
that as it's more invasive and would require a roundtrip back to the
client. Instead, this commit simply stops performing the forward when
the static path pattern is not /**.

Closes gh-8788

Closes gh-8294

Closes gh-8497

Closes gh-8767

* pr/8660:
  Fix test assertions

Closes gh-8660

* pr/8678:
  Fix propdeps-plugin url in doc

Closes gh-8678

* pr/8718:
  Fix typo

Closes gh-8718

Closes gh-8734

Closes gh-8733

Closes gh-8732

Closes gh-8731

Closes gh-8730

Closes gh-8729

Closes gh-8728

Closes gh-8727

Closes gh-8726

Closes gh-8725

Closes gh-8724

Closes gh-8723

Closes gh-8722

Closes gh-8721

Closes gh-8720

See gh-8713

Closes gh-7949
See gh-8712

* pr/8594:
  Polish contribution
  Fix invalid security example in doc

Closes gh-8594

Closes gh-8580

Closes gh-8620

* pr/8582:
  Improve `RedisSessionConfiguration` conditions

Closes gh-8582

Closes gh-8598

See gh-8621

Fixes gh-8602

Closes gh-8574

* pr/8562:
  Add missing spring-data-cassandra metadata

This commit adds the missing
`spring.data.cassandra.repositories.enabled` in the metadata and the
documentation.

Closes gh-8562